Conventionally, an atomized aluminum powder is used as a material for a pigment, a paste for forming an electrode, and the like. Since a variation in particle diameters of the atomized aluminum powder is large, the atomized powder cannot be used as the above-mentioned materials as it is. Therefore, the atomized aluminum powder is sieved and thereafter, is used as the above-mentioned material. Accordingly, there arises a problem in that the aluminum powder which has been sieved out and dropped (in other words, whose particle sizes are greater than or equal to a predetermined particle size and/or less than or equal to a predetermined particle size) is wasted. Therefore, in order to reuse the aluminum powder which has been sieved out and dropped, various attempts such as an attempt of melting the atomized aluminum powder have been made. However, the attempt of the melting the atomized aluminum powder with a good yield and reusing the atomized aluminum powder cannot be carried out.
Japanese Patent No. 3274931 (hereinafter, referred to as Patent Literature 1) discloses an aluminum-cuttings melting furnace with which aluminum cuttings are melted by heat of a burner and a fixed quantity thereof is retained, and a flux treatment is involved therein. In general, the aluminum cuttings are a kind of an aluminum powder which is obtained upon subjecting an aluminum molded piece to a lathe process or a cutting process and whose each particle is flake-shaped or irregular-shaped. An average particle diameter thereof is comparatively large and a specific surface area is comparatively small.